note: this is a hidden cli argument.
raw details (from release v2.2.3):
{
"name": "rpc_send_transaction_batch_size",
"properties": {
"long": "rpc-send-batch-size",
"value_name": "NUMBER",
"hidden": "hidden_unless_forced()",
"takes_value": "true",
"validator": "|s| is_within_range(s, 1..=MAX_TRANSACTION_BATCH_SIZE)",
"default_value": "&default_args.rpc_send_transaction_batch_size",
"help": "The size of transactions to be sent in batch."
},
"isDeprecated": true
}